C LIBRARY

C LIBRARY SUMMARY

DESCRIPTION

EXPORTS

This function allocates an (ETERM) structure.
Specify etype as one of the following constants:

ERL_INTEGER

ERL_U_INTEGER /* unsigned integer */

ERL_ATOM

ERL_PID /* Erlang process identifier */

ERL_PORT

ERL_REF /* Erlang reference */

ERL_LIST

ERL_EMPTY_LIST

ERL_TUPLE

ERL_BINARY

ERL_FLOAT

ERL_VARIABLE

ERL_SMALL_BIG /* bignum */

ERL_U_SMALL_BIG /* bignum */

ERL_SMALL_BIG and ERL_U_SMALL_BIG are for
creating Erlang bignums, which can contain integers of
arbitrary size. The size of an integer in Erlang is machine
dependent, but in general any integer larger than 2^28
requires a bignum.

allocated and freed are initialized to
contain information about the fix-allocator used to allocate
ETERM components. allocated is the number of blocks
currently allocated to ETERM objects. freed is the
length of the freelist, where blocks are placed when they are
released by erl_free_term() and
erl_free_compound().

Normally it is the programmer's responsibility to free each
Erlang term that has been returned from any of the
erl_interface functions. However since many of the
functions that build new Erlang terms in fact share objects
with other existing terms, it may be difficult for the
programmer to maintain pointers to all such terms in order to
free them individually.

erl_free_compound() will recursively free all of the
sub-terms associated with a given Erlang term, regardless of
whether we are still holding pointers to the sub-terms.

There is an example in the User Manual under "Building
Terms and Patterns"